Sea ice extent in Eastern Bering

Updated on June 24, 2025

The time series plot and data summary below present statistics on sea ice extent within eastern Bering Sea computed from the remote sensing data from NOAA/NSIDC on PolarWatch:

Mean (1991-2020): Represents the average sea ice extent from 1991-2020.
Upper and Lower Bounds of Error Band (1991-2020): Reflect the uncertainty of the Mean.
Current and Previous Year: Show the daily sea ice extent values for the current and previous year within the area.

Plots are interactive!

To zoom in and out, reset or download the plot, hover on the plot to see the option on the top right corner.
To turn on and off data series, click on the data series title in the legend located below each plot.

Sea ice extent daily time series

Code

# Set plot colors
plot_colors = c("#318CE7", "#F08080", "#94C973", "#cccccc", "#cccccc", "#cccccc")

xaxis <- list(title = "Dates (MM-DD)",
            type = 'category',  # Ensures correct ordering without converting to full date format
            tickformat = "%m-%d",  # Display ticks in mm-dd format
            categoryorder = "array",  # Custom order for the x-axis
            categoryarray = month_day_order,  # Sort month_day as a category
            showline = TRUE,
            showgrid = FALSE,
            tickwidth = 1,
            ticklen = 2
            )

yaxis <- list(title = "Square km",
            showgrid = TRUE,
            zeroline = FALSE,
            showline = TRUE,
            showticklabels = TRUE,
            autorange = TRUE)

# Define horizontal line specs (total area)
hline <- function(y = 0, color = "black") {
  list(
    type = "line",
    x0 = 0,
    x1 = 1,
    xref = "paper",
    y0 = y,
    y1 = y,
    line = list(color = color, dash="dot")
  )
}


thisyear_label = paste(lastyear,"/", lastyear+1)
lastyear_label = paste(lastyear-1, "/", lastyear)
anom_lastyear_label = paste("Anomaly: ", substr(lastyear-1,3, 4), "/", substr(lastyear, 3,4))
anom_thisyear_label = paste("Anomaly: ", substr(lastyear,3, 4), "/", substr(lastyear+1, 3,4))

Data: Sea ice extent was computed by PolarWatch using NOAA/NSIDC daily sea ice concentration data at a 25km resolution

Sea ice extent anomalies

Users can click on the data names in the legend to toggle it on and off.

Data Source: NOAA/NSIDC Sea Ice Concentration NSIDC Climate Data Record V4 and Near-Real-Time V2, Arctic
Statistics/Figure Source : NOAA CoastWatch PolarWatch

Data and plot downloads

Annualized Sea ice extent time series (1985-2024)

Data: Sea ice extent anomalies were computed by PolarWatch using NOAA/NSIDC monthly sea ice concentration data at a 25km resolution

Data and Methods

The data sources and calculation methods can be found on the methods page. (Methods).

Data Disclaimer

The extent values for this year are computed using near real-time data, while the science-quality data (Climate Data Record, or CDR) is still being processed and will be available at a later time.

Data may be missing or corrupted in the event of technical failures with sensors or ground stations.

Please check the data log or contact us at sun.bak-hospital@noaa.gov for further information.

Daily Sea ice extent data downloads

Baseline daily extent time series (1991-2020) Data - Metadata
Near-real-time daily extent of two recent years Data - Metadata
Annual mean extent time series (1985-2024) Data - Metadata
Daily sea ice concentration from near-real-time (NRT) Link to Portal
Daily sea ice concentration from Climate Data Record (CDR) Link to Portal

More resources

NOAA’s Annual Arctic Report Card